Repeater control system



July 6, 1948. H. G. BuslGNlEs 2,444,426

REPEATER coNTnoL SYSTEM Filed oct. 26, 1945 7/10 ze Y J SIGNAL 9/ A/0/scR/M/A/Am@ 40- Je M 172) 24 J7 I5 I 05756701? 06E/LANDI? 18r 54 f. L POWER coNrRal. UN/ A @any j/ i gn @v/cf 6 l 2? 42 a L i C Lum il 2ow POWER 68| SUFCE 212 SIGN/1l G'ENEHTOR l- J0 RECE/ VEO lM` M :4L M` ,IL M` M` /GNAL if L i k l L k l I Osc/L LA T012 df-Z/r @Anon 80a 80 @ab l TRA/v M T E0 e VK FMk-IL n V( T A1521 INVENToR.

Patented July 6, 1948 REPEATER CONTROL SYSTEBE Henri G.' Busignies, ForestHills, N. Y., assigner v to Federal Telephone and Radio Corporation,

New York," N. Y., a` corporation of Delaware Application October 26, 1943, Serial No. 507,704

(Cl. Z50-15) Claims.

This invention relates to radio control devices and more particularly to those devices adapted to be triggered into operation by a given radio signal.

In the copending application of Edmond M. Deloraine, for lEtadiolocat-ing systems, Serial No; 507,664, filed of evendate, a system is disclosed which includes a radio locating device and a plurality of' location repeaters. The location repeaters are adapted to be positioned at pointsl the location of which with respect to the locating device is to be determined when desired within either a few hours or a few days at most from the time of their positioning. Each repeater is provided with means triggerable only by a givenv signal, intended to be transmitted' by the radio locating device, and means to-transmit a return signal of a given characteristic identifying the repeater. The radio. locating device is provided with means to detect the repeater signal, to de-J termine the identity of the repeater transmitting same and also the directionV and'distance to such repeater.

It is an object of this invention to provide a power controly arrangement for such location repeaters as above referred to so as to prolong considerably the useful period thereof Without adding materially to the size and'weight of the repeater as would be the case where additional batteries are provided.

The above and other objects of the invention will become more apparent upon reference to the following detailed description tofbe read in connection with the accompanying drawing, in which:

Fig. l is a schematic block diagram of a lo-K cation repeater according to the principles `of this invention; and

Fig. 2 is a graphical illustration useful in explaining the operation of the repeater.

The location repeater shown in Fig. 1 is constructed to form a small compact unit and since the system operates preferably at ultra high frequencies', it is provided'with a relatively small antenna l0. The antennay is used both for receivgering impulse a signal having a given characteristic which may be used for identifying the repeater. In the aforementioned copending Deloraine application, several forms of signal generators are disclosed any one of which is appropriate. For purposes of illustration, however, I have indicated by curve d of Fig. 2 a square pulse signal which may be produced by the known dip-flop type of multivibrator wherein the multivibrator is adapted to return from a secondV state of operation to its normal state of operation in a given period' of time each time it is triggered from the normal state of operation to said second state of operation. By adjusting the time constants of the multivibrator circuit, it is possi-ble to produce a pulse of a predetermined width useful as the identifying signal for the repeater.

The output of the signal generator 22 is applied to an oscillator 23 whereby the signals produced by the generator operate as modulating energy for the oscillator in a manner well known. The output 2li of the oscillator 23 is connected to the antenna iii. Since the output signal of the oscillator 23 is preferably different in frequency or form' from the triggering signal, no blocking circuit between the oscillator and detector need be provided.

The repeater receives its main power supply from source 25 which preferably consists of a battery of the necessary voltage. This source is continually connected by lines 25, 2l and 28 to energize the detector lll, the signal discriminator l5 and the power control unit 2D. The supply of f power to generator 22 and the oscillator' 23 is controlled by unit 2u, aswill be described in detail hereinafter.

`It may be assumed that the location repeater of Fig; 1 is arranged to be triggered by a triggering signal 3i) made up of two pulses 3l and 32 separated'bya given time interval t1. Upon detection of the triggering signal 30, the pulses of the signal are applied to the discriminator I5 which comprises'a parallel circuit one branch of which includes a delay device Sli, the two branches terminating at' separate grids 3E' and 31 in a vacuum tube 3B. The plate electrode 3S is connected to the line i8 and to a source of positive current through resistor di), The cathode 35 is heated by power supplied over lines 2li and 21 from source 25. The grid 3l is biased negatively by a negative source of potential through a resistor 42. whereby the tube 38 is normally biased to cut-off and is non-responsive to the inputienergy of 'a single pulse,

The delay device 34 is of such retardation characteristics as to retard the pulse energy applied thereto by a time interval equal to the interval t1. Thus, the retardation applied to pulse 3| of the signal 30 in passing through the delay device 34 will cause pulse 3| to reach the grid 31 at the same time pulse 32 reaches the grid 36. This coincidence of the energy of pulses 3| and 32 overcomes the negative bias on the tube sufficient to produce a single output pulse 43. Other combinations of pulses having larger or smaller intervals therebetween than interval t1 will not operate the tube 38 since the pulse energy will not occur in coincidence on the grids 36 and 31.

Assuming that the tube 38 has been triggered by a signal 3|! thereby producing pulse energy 43, it will be observed that the latter will be applied t the power control unit 2|) and to the signal generator 22. The signal generator 22, however, will not respond to the pulse energy 43 since the power supply to the generator is controlled by relay contacts 55, 5| which connect the source 25 to the generator through lines 28 and 52. The power control unit 26, however, will be triggered since the cathode 53 of the gas-filled tube 54 thereof is supplied with power from the source 25 over line 28. The plate 60 of the tube 54 is connected through relay coil 62 to a source of positive current through resistor 64. The grid 55 is connected through a coupling condenser 61 to the line I8 and is also supplied with a negative bias through resistor 68.

The supply of power to the oscillator 23 is also controlled by relay contacts 50, 5|, the oscillator being connected to contact 5| through line 69.

The operation of the location repeater will best be understood by reference to Fig. 2. Curve a represents a series of triggering signals 35 transmitted for the purpose of locating the repeater. When these pulses are detected at I4 and applied to the signal discriminator I6, corresponding pulses 43 (curve b) are produced one for each of the triggering signals 30. The pulses 43 are applied in succession on the grid 65 of the tube 54. The tube 54 will nre in response to each pulse 43 and due to the time constant of the self biasing resistance-capacity circuit 10 will Icontinue to fire for a period sucient to actuate the relay elements 62, 50. The relay coil 62 is preferably of the slow release type so that when once closed it will remain closed as long as signal pulses 30 are received, the repetition frequency of the signals 30 being such as to cause the tube 54 to lire shortly before the relay coil 62 would normally release the contact 50.

When the pulse energy 43 of curve b is first applied to the tube 54 thereby causing closure of the relay contacts 50, 5| power from the source 25 is applied through line 2S, contacts 50, 5| and line 52 to the signal generator 22, and from contact 5| through line 69 to the oscillator 23.

Due to the interval required to heat up the filaments of the vacuum tubes contained in the generator 22 and the oscillator 23, there will be a lapse of time before the repeater will transmit an identifying signal. 'I'his heating up period is indicated by the portion of the curve c. The portion 16 of the curve c represents the interval during which the generator 22 and the oscillator 23 are heated satisfactorily for operation. As soon as this heated condition is reached, the generator 22 and the oscillator 23 will operate to transmit a characteristic pulse signal 80 in response to each of the succeeding triggering signals such as indicated at 86a for signal 30a. As shown by broken line 8|, there will be a time interval t2 between the reception of signal 30a and the transmission of repeater pulse 80a. This time period, of course, will depend on the operation of the discriminator I6 and the time required for generation and transmission of the repeater signal.

This repeating function of the repeater will continue until the signals 30 are discontinued as indicated at 3012. Thus, the last repeater signal will be the pulse 80h corresponding to the last signal pulse 30h. The power supply 25 will be discontinued to thek generator and oscillator a short interval after the discontinuance of triggering signals thereby permtting the filaments of the tubes of the generator and oscillator to cool as indicated by the portion 14 of the curve c.

It will be apparent from the foregoing description, that the power control feature of the invention prolongs the energy of a given power supply for a much longer period than if the power supply were connected directly to the filaments of all parts 0f the repeater.

While I have shown specific apparatus for performing the power control function of my invention, it will be understood by those skilled in the art that many other arrangements may be made whereby the power supply is controlled in response to a given triggering signal. For example, instead of using a slow release relay, the gaslled tube 54 may be arranged to fire for periods longer than the intervals between successive triggering signals. Switching means other than the relay and gas-filled tube arrangement shown may, of course, be used, so long as they provide the requisite timing for the power supply, without departing from the invention. It is to be understood, therefore, that the apparatus herein 4 0 illustrated and described is to be regarded as illustrative of the invention only and ing the scope of the object.

I claim:

l. In a, location repeater of the character having transmitting means including la signal generator to produce for transmission pulse signals of a given character identifying said repeater and receiving means responsive only to pulse signals of a given repetition rate to cause flow of energy for controlling operation of said signal generator; a power supply, means connecting said power supply to said receiver means to energize the same continuously for normal response to said given repetition rate pulse signals, relay means energizable to connect said power supply to said transmitting means, and control means comprising an electron discharge device respon sive to said flow of energy at said given repetition rate to energize said relay means.

2. The repeater defined in claim l wherein the transmitting means includes an oscillator coupled to said signal generator for modulation by the pulse .output thereof, andsaid relay means includes contact means for controlling the supply of power to both said oscillator and said signal generator.

3. In a location repeater of the character having transmitting means including a signal generator to produce for transmission a signal of a given character identifying said repeater and receiving means responsive only to pulse signals of a given repetition rate to produce a synchronizing pulse in response to each pulse signal of a given repetition rate for controlling operation of said signal generator; e, power supply, means not as limitconnecting said power supply to said receiver means to energize the same continuously for normal response to said given repetition rate pulse signals, coupling means comprising an electron discharge device operable between coupling and non-coupling condi-tions for controlling flow of energy from said power supply to said transmitting means, and means responsive to the occurrence of a train of synchronizing pulses from said receiving means to actuate said coupling means from non-coupling condition to coupling condition and means responsive to the failure of occurrence of said pulse signals at said given repetition rate to effect return of said coupling means to non-coupling condition.

4. In a location repeater of the character having transmitting means including a signal generator to produce for transmission a signal of a given character identifying said repeater and receiving means responsive only to given triggering signals to cause iiow of energy for controlling operation of said signal generator; a power supply, means connecting said power supply to said receiver means to energize the same continuously for normal response to said given triggering signals, relay means energizable to connect said power supply to said transmitting means, and control means responsive to said ow of energy to energize said relay means, said control means including a gas-lled tube having plate and cathode electrodes thereof connected in circuit with said relay and the grid electrode thereof connected to the .output of said receiver means, whereby said flow of energy causes said tube to fire and means for biasing said tube to prolong the firing thereof for a given period sufcient to operate said relay means.

5. A location repeater of the character having an oscillator, a signal generator for producing a signal of a given characteristic identifying said repeater, means for applying the repeater signals thus produced to said oscillator to modulate the output thereof, receiver means for detecting pulse signals, and a signal discriminator responsive to detection of pulses of a given repetition rate, a power supply, control means comprising an electron discharge device responsive to said discriminator for controlling at said given repetition rate the application of power from said power supply to said oscillator and to said generator, and means for connecting said power supply to said receiver means, said discriminator and said control means to maintain the receiver, discriminator and control means continuously in energized condition preparatory to detection of pulse signals.

HENRI G. BUSIGNIES.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,702,423 Wensley Feb. 19, 1929 1,947,018 Plastino Feb. 13, 1934 2,047,531 Ardenne July 14, 1936 2,152,329 Schussler Mar. 28, 1939 2,165,063 MacKay July 4, 1939 2,211,942 White Aug. 20, 1940 2,223,049 Reichle Nov. 26, 1940 2,266,401 Reeves Dec. 16, 1941 2,287,044 Kroger June 23, 1942 FOREIGN PATENTS Number Country Date 337,469 Great Britain Nov. 3, 1930 

